Artificial arm



J. C. AVENl ARTIFICIAL ARM May 13, 1958 3 Sheets-Sheet 1 Original FiledJan. 27. 1951 1210922308 Josepov Qflveaezl, by J1 J. c. AVENl ARTIFICIALARM May 13, 1958 3 Sheets-Sheet 2 Original Filed Jan. 27, 1951 .I H Illnl lu rd V & m

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J. C. AVENI ARTIFICIAL ARM May 13, 1958 3 Sheets-Sheet 3 Original FiledJan. 27, 1951 Josepfa, C. dive-jail,

United States Patent 2,834,024 ARTIFICIAL ARM Joseph C. Aveni, Melrose,Mass.

Continuation of application Serial No. 208,199, January 27, 1951. Thisapplication Slitfillir 10, 1954, Serial No. 455,162

2 Claims. (Cl. 3-12) This invention relates to jointed artificial armsand particularly to control means therefor to enable either the grippingdevice or the arm flexing to be operated by the wearer independently ofor in conjunction with the other and regardless of whether such otherhas been operated and which are adaptable both to individualrequirements and general requirements of lightness in Weight, strength,and ease of operation. The present application is a continuation of mycopending application, Serial No. 208,199, filed January 27, 1951, andnow abandoned.

It is widely appreciated that a person who has lost a limb is capable ofeffectively overcoming his handicap by prosthesis. Whether thatobjective is attained is dependent on several factors. An artificialarm, for example, includes an upper arm section, a forearm section, anda suitable connection between those sections enabling the arm to besuitably bent and straightened. An artificial hand or other grippingdevice is attached to the free end of the forearm section while theupper end of the upper arm section is attached by harness to the wearersbody and is provided with a stump receiving socket. Various means havebeen employed to enable the arm to be flexed and the gripping device tobe actuated by movement of either or both shoulders.

It is self evident that an artificial arm must combine strength,lightness in weight, and ease of operation to enable the wearer toreally overcome his handicap and artificial arms that have been proposedhave not adequantely met those general requirements.

An underlying cause of inadequacy is the failure to recognize that eacharm loss presents individual problems and these are well exemplified byvariations in stump length. While the socket of each upper arm sectionmust be shaped for the stump which it is to fit, it must be kept in mindthat the utility of the stump in artificial arm manipulation, the natureof the attaching harness, and extent of motion that the wearer caneifect depend on the length and strength of the stump. Such factors makeessential that the arm flexing and gripping device operating means beadapted to limitations imposed by the nature of the injury and at thesame time lend themselves to meeting the more readily appreciatedrequire ments to which I have referred.

In addition, it will be understood that in order for the wearer to beable to use his artificial arm with real effectiveness, the control ofarm flexing and the control of gripping device operation must, at alltimes, be capable both of separate actuation or of actuation inconjunction with each other. A common objection to existing artificialarms is that the gripping device is actuated when the arm is flexed andthat the arm is flexed when the gripping device is operated unless anelbow lock is employed.

An arm in accordance with the invention thus meets the principalobjective that a pull on the device actuating cord is inoperative toflex the arm while a .pull on the other cord is only efiective to flexthe arm. Both cords may be actuated together and either may be actuatedindependently of the other so that the arm may be flexed or straightenedwhether ornot the gripping device is actuated and the gripping devicemay be controlled as desired whether the arm is flexed or straightened.

At the same time, the invention is readily adaptable to meet individualrequirements such as are imposed by the stump and makes possibleartificial arms that are of simple Construction and Combine adequatestrength, lightness in weight, and maximum ease of operation.

in the'accornpanying drawings, there is shown an-illustrative embodimentof the invention from which these and other of its novel features andadvantages will be readily appreciated.

in the drawings:

Fig. 1 is a'view of an artificial arm, in accordance with the invention,showing it harnessed to a wearer, as seen from the front.

Fig. 2 is a corresponding rear view.

Fig. 3 is a view, on an enlarged scale, showing the arm as seen from theside that is disposed towards the wearers body and illustrating theoperation of the gripping device.

Fig. 4 is a view, on the same scale, of the arm as viewed from thefront.

Fig. 5 is a view similar to Fig. 3 but showing the parts in section.

Fig. 6 is a view, also similar to Fig. 3, but illustrating the flexingof the arm. I

Fig. 7 is a section along the lines 7 7 of Fig. 4, and

Fig. 8 is a fragmentary and partly sectioned view, on a furtherincreased scale, showing a preferred form of means to interconnect thearm sections.

In the embodiment of the invention shown in the drawings, there isgenerally indicated the hollow fore and upper arm sections at 10 and 11,respectively. While the arm sections may be made from anysuitable'material that is light in weight and has suflicient strength,plastic impregnated glass cloth has been found to possess both of thesenecessary characteristics to an extent making that material stronglypreferred.

The upper end of the arm section 11 constitutes a socket generallyindicated at 12 molded to fit the stump 13 of the wearers arm. Stumpsvary, of course, as to size and shape and are a factor determining thedetails of artificial arm and attaching harness construction and alsothe extent of motion in the artificial arm that the wearer can efiect.The other end 14 of the arm section 11 is preferably both tapered androunded and formed with parallel slots 15 and 16 extending from front toback, as may be seen in Fig. 4.

The lower end of the fore arm section 10 has a support 17 detachablymounting a gripping device 18 which is partially rotatable relative tothe forearm section 10. As the support 17 and the gripping device 18 arenot a part of the invention, these are not detailed but reference ismade to the lever 19 as illustrative of means by which such devices areoperated. The upper end of the fore arm section 10 is shown as receivingfreely within it the closed end 14 of the upper arm section 11 and theseare connected by elbow simulating means, generally indicated at 20,enabling the arm to be flexed. The arm may be operated effectively withor without an elbow lock.

As :it is important both that an artificial arm be capable of beingflexed sufliciently to enable objects to be raised to the wearer's mouthand incapable of being bent rearwardly beyond a predeterminedstraightened position, it is preferred that the connecting means shownin the drawings and detailed in Figs. 7 and 8 be used.

There is shown, on each side of the arm, a forwardly extending member 21attached in the upper arm section'- r 2,834,024" Patented -May 13, 195811 and a rearwardly extending arm 22 anchored to the fore arm section10. The members 21 and 22, on each side, are pivotably connected as at23 and 24, respectively, to a link 25 which is slotted at each end toreceive the L-shaped portions 26 of each member and to provide apartition or stop 27 engageable by the portions 26 to prevent the armfrom being straightened beyond a predetermined position while enablingthe fore arm section 21 to swing on either or both pivots. The fore armsection is shown as cut away as at 23 to further ensure that the arm maybe sufliciently flexed. The members 21 and 22 are shown as bonded inplace by the plastic with which the cloth is impregnated and for thatreason are provided with holes 29.

Adjacent the lower end of the stump socket 12, the front portion of thearm section 11 is provided with an aperture 30 and the back portionthereof with an aperture 31, both of which may be provided with a metaleyelet 32. The front of the forearm section 10 is formed with atransverse slot 33 of a length equal to the travel of the lever 19 asthe gripping device is turned from one extreme position of use toanother. At the front edge of the slot 33, there is shown a lip 34defining an anti-friction guide surface for the end of the cord 35 thatis to be attached to the lever 19 of the gripping device. The cord 35 ishoused by the arm sections and passes through the slot and is exposedthrough the aperture 30 for attachment to the adjustable harness strap36.

A second cord 37 is housed in the arm section 11. At its front end, thecord 37 is anchored as at 38 to the forearm section It and extendsthrough the slot 16 and rearwardly through the aperture 31 where it isexposed for attachment to the adjustable harness strap 39.

In accordance with the invention, there is provided means in the armlocating the cord 35 on the side, opposite the aperture 30, of the pivotcenter of the connecting means that is adjacent the lower end of the armsection 11 and the cord 37 on the side of that center that is oppositeits aperture 31. This ensures that the cord 35 is disposed so that,whether the arm is flexed or straightened, a pull on it to operate thegripping device will not affect the position of the forearm section 10and so that, whether or not the gripping device is operated, a pull onthe cord 37 will flex the arm.

This objective may be attained in various ways but the means, for sodoing, shown in the drawings is preferred. In practice, a singletransverse member constitutes the pivot 23 between the links and arms 21on both sides of the arm. A pivot 23 is employed to rotatably support apulley 40 within the arm section 11. The pulley 40 is located on thepivot 23 in alinement with the slot 15 by a spacing sleeve 41 whichengages one of the hub ends 42 of the pulley 40. I effect the desiredspacing of the cords in this embodiment of my invention, by training'thecord under the pulley and by disposing the cord 37 over the sleeve 41.This structure ensures excellent anti-friction support for both cords.

In practice, it is preferred that a pulley 43 be mounted on the innersurface of the arm section 11 and adjacent the aperture 31 to ensure aminimum of frictional resistance to movement of the cord 37 which istrained under the pulley 43. The term cord is used herein to include anysuitable flexible connecting strip but, in practice, nylon cord ispreferred.

While the nature of the harness depends to a substantial extent on therequirements of each individual, a strap 44 is shown as connected to thearm section 11 adjacent its upper end at the front and back to straddlethe shoulder with a strap 45 connected to the intermediate part of thestrap 44 and the arm section 11. The strap 44 has a loop 46 to slidablyreceive the harness strap 36 which, as may be seen in Figs. 1 and 2.,extends across the back of the wearers neck and forwardly and downwardlyaround the other shoulder from which point it lies up- 4 wardly acrossthe back and is anchored to the strap 44. Adjacent its anchorage to thestrap 44, the adjustable harness straps 36 and 39 are interconnected.The harness shown in the drawings forms no part of this invention, butis preferred because of its simplicity and because it well illustratesthe use of artificial arms in accordance with the invention. Y

Both in flexing of the arm and the opening and closing of the grippingdevice, shoulder movements are employed to loosen and tighten theharness to exert pulls on the cords or to loosen them. It will beappreciated that a pull on the cord 35 is effective to open thegripping. de vice while a pull on the cord 37 causes the fore armsection 10 to swing upwardly.

As both cords are housed within the arm sections in the zone whereclothing might interfere with their movement and both are trained overand supported in proper position by anti-friction members, it will beappreciated that theyv may be actuated with a minimum of resistance. Itwill thus be appreciated that artificial arms in accordance with theinvention are well adapted to meet the general requirements of strength,lightness in weight, and ease of operation. The invention also makespossible the adaptation of arms made in accordance therewith toindividual requirements as the cords may pass outwardly through theupper arm section adjacent the bottom of the stump socket regardless ofthe length of the stump without any change in the elbow simulatingconnection.

It will be apparent, however, that the length of the stump makesnecessary certain changes as in practice it is necessary to locate theapertures 30 and 31 as close as possible to the bottom of the stumpsocket 12. With a stump longer than that indicated in the drawings, theapertures 30 and 31 would be located correspondingly nearer the pivotcenter established by the pivot 23 and, in such instances, the diameterof the pulley 40 is decreased.

Attention is directed to the slots 15 and 16 in the lower end 14 of theupper arm section. As will be apparent from Fig. 6, these slotsaccommodate the cords 35 and 37 when the arm is flexed and are utilizedto minimize the amount of stock that is removed from the end 14. As willbe apparent from Fig. 4, the slot 16-is shown as considerably wider thanthe slot 15. The reason for this is that it is desirable to have thecord 37 extend as straight as possible from its point of attachment tothe harness strap 36 to the fore arm section 10. While its dispositionis dependent on individual requirements, the cord 37 usually extendsdiagonally relative to the pivot axis, see Figs. 2 and 4, and is securedto the fore arm section 10 somewhat on the outside of its front portionand necessitates a relatively wide slot to prevent binding during armflexing.

What I therefore claim and desire to secure by Letters Patent is:

1. Au artificial arm for use with a gripping device and with asupporting harness, said arm comprising a hollow upper arm sectionhaving a stump receiving socket at its upper end, a hollow forearmsection including at one end a device receiving support, means pivotallyconnecting the other ends of said arm sections so that said arm may beflexed from a predetermined straightened position with a pivot center atthe lower end of said upper arm section, the front portion of saidforearm section having an opening extending forwardly from its connectedend and being dimensioned and located to enable said arm to be flexed toan extent approximately equal to that of a normal human arm, and arelatively wide transversely disposed slot adjacent said support in lthe front part of the side of said forearm section, said upper armsection having a first aperture in its front portion and a secondaperture in its back portion located between'the bottom of said socketand said center, an arm flexing cord attached at one end to the frontportion of said forearm section adjacent the front end of said openingand extending freely into said upper arm section and directly throt ghsaid second aperture for attachment to said harness, said meansincluding a pulley and a transverse supporting shaft mounted in thelower end of said upper arm section over which shaft said cord extends,and a second cord in said arm trained under said pulley with one endextending directly through said slot for attachment to said device andthe other end extending directly through said first aperture forattachment to said harness.

2. An artificial arm for use with a gripping device and with asupporting harness, said arm comprising a hollow upper arm sectionhaving a stump receiving socket at its upper end, a hollow forearmsection including at one end a device receiving support, means pivotallyconnecting the other ends of said arm sections so that said arm may beflexed from a predetermined straightened position, the front portion ofsaid forearm section having an opening extending forwardly from itsconnected end and being dimensioned and located to enable said arm to beflexed to an extent approximately equal to that of a normal human arm,and a relatively wide, transversely disposed slot adjacent said supportin the front part of the side of said forearm section, said upper armsection having an aperture in its front portion located between thebottom of said socket and said center, said means including a rotatablemember mounted in the lower end of said upper arm section and a deviceoperating cord in said arm trained around said rotatable means with oneend extending directly through said slot for attachment to said deviceand its other end extending directly through said aperture forattachment to said harness.

References Cited in the file of this patent UNITED STATES PATENTS CarnesDec. 10, 1912

